CD23 explained

CD23, also known as Fc epsilon RII, or FcεRII, is the "low-affinity" receptor for IgE, an antibody isotype involved in allergy and resistance to parasites, and is important in regulation of IgE levels. Unlike many of the antibody receptors, CD23 is a C-type lectin. It is found on mature B cells, activated macrophages, eosinophils, follicular dendritic cells, and platelets.

There are two forms of CD23: CD23a and CD23b. CD23a is present on follicular B cells, whereas CD23b requires IL-4 to be expressed on T-cells, monocytes, Langerhans cells, eosinophils, and macrophages.^[1]

Function

CD23 is known to have a role of transportation in antibody feedback regulation. Antigens which enter the blood stream can be captured by antigen specific IgE antibodies. The IgE immune complexes that are formed bind to CD23 molecules on B cells, and are transported to the B cell follicles of the spleen. The antigen is then transferred from CD23+ B cells to CD11c+ antigen presenting cells. The CD11c+ cells in turn present the antigen to CD4+ T cells, which can lead to an enhanced antibody response.^[2]

Clinical significance

The allergen responsible in dust mite allergy—Der p 1—is known to cleave CD23 from a cell’s surface. As CD23 is soluble, it can move freely and interact with cells in plasma. Recent studies have shown that increased levels of soluble CD23 cause the recruitment of non-sensitised B-cells in the presentation of antigen peptides to allergen-specific B-cells, therefore increasing the production of allergen specific IgE. IgE, in turn, is known to upregulate the cellular expression of CD23 and Fc epsilon RI (high-affinity IgE receptor).^[3]

In flow cytometry, CD23 is helpful in the differentiation of chronic lymphocytic leukemia (CD23-positive) from mantle cell lymphoma (CD23-negative).^[4] CD23 can also be demonstrated in germinal centre follicular dendritic cells using immunohistochemistry but is minimally expressed by benign germinal center B cells. In contrast to neoplastic mantle cells (which are negative for CD23), the resting cells of physiologic mantle zone express CD23. Paradoxically, Lymphomas arising from the mantle zone are generally negative for CD23, while most B-cell chronic lymphomocytic leukaemias are positive, allowing immunohistochemistry to distinguish these conditions, which otherwise have a similar appearance. Reed – Sternberg cells are usually positive for CD23.^[5]

See also

• Cluster of differentiation, a list of all the CD-numbered proteins

Further reading

• Kijimoto-Ochiai S . CD23 (the low-affinity IgE receptor) as a C-type lectin: a multidomain and multifunctional molecule . Cellular and Molecular Life Sciences . 59 . 4 . 648–64 . Apr 2002 . 12022472 . 10.1007/s00018-002-8455-1 . 20040394 .
• Schwarzmeier JD, Hubmann R, Düchler M, Jäger U, Shehata M . Regulation of CD23 expression by Notch2 in B-cell chronic lymphocytic leukemia . Leukemia & Lymphoma . 46 . 2 . 157–65 . Feb 2005 . 15621797 . 10.1080/10428190400010742 . 36863790 .
• Maekawa N, Kawabe T, Sugie K, Kawakami T, Iwata S, Uchida A, Yodoi J . Induction of Fc epsilon RII/CD23 on PHA-activated human peripheral blood T lymphocytes and the association of Fyn tyrosine kinase with Fc epsilon RII/CD23 . Research in Immunology . 143 . 4 . 422–5 . May 1992 . 1387715 . 10.1016/S0923-2494(05)80075-6 .
• Rose K, Turcatti G, Graber P, Pochon S, Regamey PO, Jansen KU, Magnenat E, Aubonney N, Bonnefoy JY . Partial characterization of natural and recombinant human soluble CD23 . The Biochemical Journal . 286 (Pt 3) . Pt 3 . 819–24 . Sep 1992 . 1417742 . 1132977 . 10.1042/bj2860819.
• Maekawa N, Kawabe T, Sugie K, Kawakami T, Maeda Y, Uchida A, Yodoi J . Induction of Fc epsilon RII/CD23 on PHA-activated human peripheral blood T lymphocytes and association of fyn tyrosine kinase with Fc epsilon RII/CD23 . International Journal of Tissue Reactions . 14 . 3 . 121–30 . 1992 . 1446976 .
• Sugie K, Kawakami T, Maeda Y, Kawabe T, Uchida A, Yodoi J . Fyn tyrosine kinase associated with Fc epsilon RII/CD23: possible multiple roles in lymphocyte activation . Proceedings of the National Academy of Sciences of the United States of America . 88 . 20 . 9132–5 . Oct 1991 . 1717997 . 52666 . 10.1073/pnas.88.20.9132 . 1991PNAS...88.9132S . free .
• Bettler B, Hofstetter H, Rao M, Yokoyama WM, Kilchherr F, Conrad DH . Molecular structure and expression of the murine lymphocyte low-affinity receptor for IgE (Fc epsilon RII) . Proceedings of the National Academy of Sciences of the United States of America . 86 . 19 . 7566–70 . Oct 1989 . 2529542 . 298106 . 10.1073/pnas.86.19.7566 . free .
• Kikutani H, Inui S, Sato R, Barsumian EL, Owaki H, Yamasaki K, Kaisho T, Uchibayashi N, Hardy RR, Hirano T . Molecular structure of human lymphocyte receptor for immunoglobulin E . Cell . 47 . 5 . 657–65. Dec 1986 . 2877743 . 10.1016/0092-8674(86)90508-8 . 43557507 .
• Ikuta K, Takami M, Kim CW, Honjo T, Miyoshi T, Tagaya Y, Kawabe T, Yodoi J . Human lymphocyte Fc receptor for IgE: sequence homology of its cloned cDNA with animal lectins . Proceedings of the National Academy of Sciences of the United States of America . 84 . 3 . 819–23 . Feb 1987 . 2949326 . 304307 . 10.1073/pnas.84.3.819 . 1987PNAS...84..819I . free .
• Yokota A, Kikutani H, Tanaka T, Sato R, Barsumian EL, Suemura M, Kishimoto T . Two species of human Fc epsilon receptor II (Fc epsilon RII/CD23): tissue-specific and IL-4-specific regulation of gene expression . Cell . 55 . 4 . 611–8 . Nov 1988 . 2972386 . 10.1016/0092-8674(88)90219-X . 140208582 .
• Lüdin C, Hofstetter H, Sarfati M, Levy CA, Suter U, Alaimo D, Kilchherr E, Frost H, Delespesse G . Cloning and expression of the cDNA coding for a human lymphocyte IgE receptor . The EMBO Journal . 6 . 1 . 109–14 . Jan 1987 . 3034567 . 553364 . 10.1002/j.1460-2075.1987.tb04726.x.
• Aubry JP, Pochon S, Gauchat JF, Nueda-Marin A, Holers VM, Graber P, Siegfried C, Bonnefoy JY . CD23 interacts with a new functional extracytoplasmic domain involving N-linked oligosaccharides on CD21 . Journal of Immunology . 152 . 12 . 5806–13 . Jun 1994 . 10.4049/jimmunol.152.12.5806 . 7515913 . 42434103 . free .
• Lecoanet-Henchoz S, Gauchat JF, Aubry JP, Graber P, Life P, Paul-Eugene N, Ferrua B, Corbi AL, Dugas B, Plater-Zyberk C . CD23 regulates monocyte activation through a novel interaction with the adhesion molecules CD11b-CD18 and CD11c-CD18 . Immunity . 3 . 1 . 119–25 . Jul 1995 . 7621072 . 10.1016/1074-7613(95)90164-7 . free .
• Maruyama K, Sugano S . Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides . Gene . 138 . 1–2 . 171–4 . Jan 1994 . 8125298 . 10.1016/0378-1119(94)90802-8 .
• Padlan EA, Helm BA . Modeling of the lectin-homology domains of the human and murine low-affinity Fc epsilon receptor (Fc epsilon RII/CD23) . Receptor . 3 . 4 . 325–41 . 1994 . 8142907 .
• Trask B, Fertitta A, Christensen M, Youngblom J, Bergmann A, Copeland A, de Jong P, Mohrenweiser H, Olsen A, Carrano A . Fluorescence in situ hybridization mapping of human chromosome 19: cytogenetic band location of 540 cosmids and 70 genes or DNA markers . Genomics . 15 . 1 . 133–45 . Jan 1993 . 8432525 . 10.1006/geno.1993.1021 .
• Chirmule N, Kalyanaraman VS, Lederman S, Oyaizu N, Yagura H, Yellin MJ, Chess L, Pahwa S . HIV-gp 160-induced T cell-dependent B cell differentiation. Role of T cell-B cell activation molecule and IL-6 . Journal of Immunology . 150 . 6 . 2478–86 . Mar 1993 . 10.4049/jimmunol.150.6.2478 . 8450224 . 25128583 .
• Förster HH, Wäsch R, Kretschmar T, Mischke D, Uchańska-Ziegler B, Ziegler A, Schmitt M, Wahn HU . Genetic markers on chromosome 19p and prenatal diagnosis of HLA class II-deficient combined immunodeficiency . Pediatric Research . 38 . 5 . 812–6 . Nov 1995 . 8552454 . 10.1203/00006450-199511000-00029 . free .
• Bajorath J, Aruffo A . Structure-based modeling of the ligand binding domain of the human cell surface receptor CD23 and comparison of two independently derived molecular models . Protein Science . 5 . 2 . 240–7 . Feb 1996 . 8745401 . 2143337 . 10.1002/pro.5560050207 .
• Frémeaux-Bacchi V, Bernard I, Maillet F, Mani JC, Fontaine M, Bonnefoy JY, Kazatchkine MD, Fischer E . Human lymphocytes shed a soluble form of CD21 (the C3dg/Epstein-Barr virus receptor, CR2) that binds iC3b and CD23 . European Journal of Immunology . 26 . 7 . 1497–503 . Jul 1996 . 8766552 . 10.1002/eji.1830260714 . 31793325 .

External links

• • PDBe-KB provides an overview of all the structure information available in the PDB for Human Low affinity immunoglobulin epsilon Fc receptor

Notes and References

1. Book: Lichtman AH, Abbas AK . Cellular and molecular immunology . Saunders . Philadelphia . 2003 . 324–325 . 0-7216-0008-5 .
2. Henningsson F, Ding Z, Dahlin JS, Linkevicius M, Carlsson F, Grönvik KO, Hallgren J, Heyman B . IgE-mediated enhancement of CD4+ T cell responses in mice requires antigen presentation by CD11c+ cells and not by B cells . PLOS ONE . 6 . 7 . e21760 . 2011 . 21765910 . 3130775 . 10.1371/journal.pone.0021760 . Metzger . Dennis W. . 2011PLoSO...621760H . free .
3. Engeroff P, Vogel M . The role of CD23 in the regulation of allergic responses . Allergy . 76 . 7 . 1981–1989 . July 2021 . 33378583 . 8359454 . 10.1111/all.14724 .
4. Barna G, Reiniger L, Tátrai P, Kopper L, Matolcsy A . The cut-off levels of CD23 expression in the differential diagnosis of MCL and CLL . Hematological Oncology . 26 . 3 . 167–70 . Sep 2008 . 18381689 . 10.1002/hon.855 . 20572446 .
5. Book: Cooper K, Leong AS . Manual of diagnostic antibodies for immunohistology . Greenwich Medical Media . London . 2003 . 1-84110-100-1 . 95 .